Liam hedges



Unit-ED drier-es imt' PATENT O rrrone COMPOSITION FOR :EARlNG-SURFACES.

srncmionzrron forming w Letterskatent;N0.A4I;556;dated seesaw-25,1890 Applicntion filedllnly 1.71; 1890. Serial No. 359,083. (liq specimens.)Patented in England July 15, 1889, No.'1l,832-

To all whom it may concern.-

' of the Queen of Great Britain, residing at Queen Annes Gate,Westminster, in the county of Middlesex, England, have invented animproved material for the construction of bearing-surfaces, applicablealso to the brushes and commutators of dynamoelectro machines,'(forwhich, I have obtained a patent in Great Britain, No. 11,332, bearingdate July 15,'1889,) of which the following is a specification.

My invention relates to the manufacture of a new anti-friction material,@ufiblbtlug of a mixture of carbon and mica, or carbon and steatite, orcarbon and soapstone, which material is applicableto the bearings andother rubbing-surfaces of alll kinds of machinery, or it may be employedfor the purpose of collecting the electric currents from the revolvingcommutator of a-dynamo.

In the manufacture of my improved material, I take of finely-powderedcarbon, plum- "25 bago, or graphite seventy-five per cent, and

add thereto twenty-fiveper cent. of powdered mica, steat-ite, orsoapstone. The mass is then incorporated with tar or sugar that willcarbonize with heat. The quantity of tar or sugar depends upon theweather and other circumstances and cannot be definitely stated. I'press the mixture into molds of the required form and bake the moldedmaterial in a manner similar to the manufacture of carbon rods. Theproportion of mica may be varied according to the density which it isdesirable to make the block and according to the useto which thematerial 3 to be applied, whether as a conductor of electricity orother- .wise. When used as a step or bearing, a

. much larger proportion of mica is used than when the substance is tobe used as a cohductor of electricity, on account of the high insulatingproperty of the mica.

When using the material for'the brushes of dynamos, I prefer forming itinto plates or rods, and inorder to reduce the electrical resistance Iinsert metallic wires or strips in the material, or I electroplate thesame. The method which I employ to hold the rp ds or plates is to passeach one through a tube or other suitable holder, the tubes or holderslying parallel to each other and being held in some frame of suitableshape which will allow each tube or holder a certain amount of play, theobject being to allow each rod or plate to be adjusted lengthwiseindependently of. the others, and also at right angles to its length, soas to bear uniformlyon the commutator. It is not necessary for the metal6o to touch the commutator, but if it does so it will wear down with thecarbon. A brush so formed may be employed in the same way as theordinary copper brushes.

My invention also relates to the following 6 5 system of constructingbrushes.

When several plates, rods, or strips are mounted side hyrside initrhesame frame or holder, I sometimes connect them all together bywire-gauze passing through the body of each. plate, rod, or stripfwh-ichmay be very conveniently efiected by embedding the metallic gauze in thematerial and baking the 1 whole. By this means the= brush is madeductivityis'impi oved. f

The arrangements above described are also applicable to brushes composedof carbon alone.

Although I have. described the application of my improved material tothe brushes of a dynamo,it can be also applied by the abovedescribedmeans of employing its conductivity to the plates or segments of thecommutator, and used with ordinary copper brushes or with brushes formedwith the improved material.

As oil, which is, practically speaking, an insulator, is not used withbearings of this description, the shaft of a dynamo and the 9c bearingare ingood electrical connection, and consequently the curren'qi'ocmingfromone end of the wire in the'cor'h'mutator may pass through thebearing to a terminal on any part of the machine in electricalconnection with the bearin I My invention is especially applicable tothe bearings and rubbing-surfaces of light machines, 'such'assewinganachines, bicycles,

&c. The. metalIpart may be fitted with a I00 lighter and more aocomm'odating and the con- 7 5-;

w movable brush which can be easily replaced i when worn, and theadvantages of obviating i the use of oil are apparent.

I claim 5 A baked compound for bearing-surfaces, applicable also to thebrushes of commutators of dynamo-electric machines, consisting offinely-powdered carbon, powdered mica, and

carbonized adhesive material of tar or sugar, substantially asdescribed.

Dated this 3d day of July, 1890.

KILLINGWORTII WILLIAM HEDGES. TH- e WALTER J. SKERTEN, GEO. J. N.FRANKLIN, Both of 17 GracechurchStv'eet,London, E. O.

Corgeetion in Letters Patent No. 441.556.

It is hereby certified that in Letters Patent No. 441,556, grantedNovember 25, 1890, upon the appucation of Killing'worth William Hedges,of Westminster, England, for an improvement in Compositions forBearing-Surfaces, an error appears in the printed specificationrequiring correction, as follows: In line 1, page 2, the word brushshould read bash and that the said Letters Patent should be read withthis correction therein that the same may conform to the record of thecase in the Patent Office. i I

Signed, countersigned, and sealed this 21st (m of April, A. D. 1891.

SEAL CYRUS BUSSEY,

Assistant Secretary of the Inter-01. Oountersigned NATHANIEL L.FROTHINGHAM,

Acting Commissioner of Patents.

